Rock drill



Oct. 6, 1931. H. C. GUSTAFSON 1,826,071

ROCK DRILL y Filed Oct. '7. 1927 3 Sheets-Sheet l 'in l v as Oct. 6, 1931. H. c. GusTAFsoN 1,826,071

' ROCK DRILL Filed Oct. '7. 1927 3 Sheets-Sheet l2.

1HE w l n il II 4 lhwlal., lllr .Um NN Oc`t. 6, 1931. H. c. GUsTAFsoN ROCK DRILL Filed Oct. 7. 1927 3 Sheets-Sheet 3 R S@ 1 "n :g

. Q1 I I A Q l@ @QQ f ki S* r s 3% i N Q f l m N Patented Oct. 6, 1931 Unirse Asra'ras PATENT oFFicE HJALMER CLARENCE eUsTAFsoN, or DENVER, ooLoaAno, AssIGNoa To GARDNER- DENVER- ooMrANYf f ROCK DRILL Application mea october 7, 1927.` serial 224,617

e The present invention relates to rook drills of the hammer type, one of the objects being to provide a structure in which the piston is better proportioned for heat treatment, so 5 that the danger of defects and breakage as a result thereof is materially reduced. Another and important object isrto provide an automatic distributing valve mechanism of short throw and quick operation, together loy with means for holding the valve in a position to maintain the piston against the tool and feed a portion of the motive fluid through such piston to the tool for hole-cleansing purposes. r

The preferred embodiment is illustrated in the accompanying drawings, wherein:-

Figure 1 is a longitudinal rsectional view through the tool with the piston in its foremost or striking position and the automatic distributing valve positioned to return the piston, v

Figure 2 is a longitudinal sectional vieW but showing the piston in its rearward position with the valve shifted to deliver motive 25 fiuid against the rear end thereof,

v e5 tions,

Figure 6 is Ia side elevation of the automatic distributing valve,

Figures 7 and 8 are cross sectional views taken respectively lon thelines 7 -7 and 8 8 1e of Figure l,

Figures '9 and v10 are 4detail views of the exhaust-controlling valve, Ashovving'it in its differentpositions,

Figure 11 is atop plan View of the exhaust port and the lIcontrolli-ng valve.

A cylinder member is employed, including a barrel 12, into the front end of which is fitted a head or spacer 13. In front of said spacer is a chuckhousing 14 that in turn carries a hood lcontaining a tool retainer 16. .Y A rotary tool receiving chuck 17 is located in the housing14 andis adapted to receive the rear end 18 of the usual drill steel or tool. r

A piston 19 reciprocates in the barrel 12 and -is provided with a reduced hammer eX- tension 20 that passes through the head 13 and isadapted tol strike against the rear end 18 of the tool. It is provided With a sliding interlocking engagement 21 with the chuck sleeve 17, 'so that upon its rotation it Will effect the rotation of such chuck sleeve and the tool in a manner Well understood. The rear end or head of the piston 19 is chambered, as shown at 22, this chamber being of substantially the same Adiameter through.- out its length, and being'located Wholly in the head. The result is that the Wall constituting the head is of substantially the same thickness throughout and is approximately the same as the front end Wall .of said head and of the hammer extension 20, said hammer extension being provided with a bore 23 extending from the chamber 22 through the front end Vof `said head. This particular form, it has been found, makes the piston peculiarly desirable for effective heat treatment. As is Well known, these pistons are heated and quenched for tempering,A .and Where there'is a thick and athin wall or section, it has been found 'very difiicult to heat the hammer slowly and evenly enough so that the centers ofthe thick and thin sections Will both reach vthe critical temperature at the same time. Then too, the operation of quenching the piston is :equally hazardous, for the reason that the thin section cools 0E much more rapidly than ydoes the thick section, and as aconsequence strains are set vup throughout the piece of steel, which though somewhat relieved by subsequent teniperng operations, are apt to remain, The result is that there is a tendency when in operation due to the constant blows and vibration, to develop cracks or fractures, and there is no method known of ascertaining these defects in advance. It has been found that with this structure, this trouble is very materially reduced.

Mounted on the rear end of the barrel 12 is a valve casing 24 backed by a head 25. This head and the housing 14 are connected by side bolts 26 and serve to tie the structure in assembled relation. The rear end of the valve casing 24 is chambered, as shown at 27 and located therein is any usual ratchet mechanism 28 for a rifle bar 29 that projects through the front end of the valve casing 24 and enters the rear end of the piston chamber 22. Threaded into said chamber 22 is a rifle nut 30 engaged with the rifle bar 29. A spacing washer or bushing 31 is interposed between the inner end of the nut 30 and the front Wall of the chamber 22. Preferably the nut 30 and spacing washer are of material light in weight, and yet not subject to great wear. It has been found that artificial resin of well-known type is peculiarly effective for the purpose. The nut 30 is made of the material commercially known as bakelite. It is much lighter in weight than steel, bronze or other material and outwears the same without creating undue wear on the rifle bar.

Motive Huid is supplied to the valve chamber through a nipple 32 opening into an internal annular groove 33 formed in the rear portion of the valve chamber. A second internal annular groove 34, located just in advance of the groove 33, is connected by a passageway 35 with the front end of the piston chamber in advance of the piston head 19. A third internal groove 36 is formed in advance of the groove 34, and is in communication with an exhaust port 37` opening through an outstanding nipple 38 formed on one side of the valve casing. In advance of the groove 36. the valve casing is provided with an internal annular chamber 39, the front wall of which i s formed by t-he rear end of the barrel 12 that fits into the valve casing.

A reciprocatorv automatic distributing valve 40 is located in the valve casing, and is provided with an annular groove 41 that is in constant communication with the groove 34. It is provided with rearwardly extending pockets 42 which afford communication between the grooves 33 and 34, when the valve is in its rearmost position, shown in Figure 5. In advance of the groove 41 the valve is provided with an annular groove 43 that moves into and out of alinement with the exhaust groove 36. Ports 44 open from the groove 43 to the interior of the valve. The front portion of said valve is provided with an enlarged counter-bore 45, producing an internal shoulder 46, the cross sectional area` of the interior of the valve behind the shoulder 46 being substantially that of the piston head 19, which is adapted to enter it, as hereinafter described. On the front end portion of the valve is an external annular flange 47 that reciprocates in the chamber 39 of the valve casing. In front of the flange 47 the valve is provided with transverse ports 48 that are movable into and out of communication with an annular groove 49 formed in the rear end of the barrel, and from this groove, ports 50 open into the front end of the flange-receiving chamber 39. The said chamber 39 has a port 51 to atmosphere. and this port is covered and uncovered by the periphery of the flange 47, as will be clear by reference to Figures 4 and 5. There is also a second port 510J to atmosphere that vents the front end of the chamber 39 when the falve moves forward and is covered by the front end of the valve as it approaches the front limit of its movement. The rear end of said flange chamber 39 is in con'nnunication with the exhaust passageway 37 by a branch passageway or port 52.

The nipple 38 in which the exhaust port 37 is formed terminates in a valve chamber 53, and in said chamber is a rotary valve 54 that is located beyond the branch 52 and is provided with a port 55 that can be moved to opened or closed position. Preferably this valve projects beyond the opposite sides of the nipple 38 and has an operating handle in the form of a yoke 56, the legs 57 of which embrace the nipple 38 and the valve 54, and are engaged in grooves 58 formed in the ends of said valve. Stop shoulders 59 formed on the ends of the nipple and engaged by the legs 57 of the yoke serve to limit the rotary movement of the valve between an opened and a closed position, all of which it is believed will be clear by reference to Figures 9, 10 and 11.

The operation of the structure is substantially as follows:

Assuming the valve in its foremost position, as shown in Figure 2, motive fluid supplied to the rear groove 33 through the nipple 32, can pass around the rear end of the valve, and operating against the rear end of the piston, will drive it forwardly. During this movement, the groove 41 affords communication between the grooves 34 and 36. Consequently air or fluid in advance ot' the piston head will escape through the passageway 35, groove 34, groove 41, groove 36 and exhaust passageway 37, to atmosphere, the valve 54 being then in open position.

As soon as the rear end of the piston clears the shoulder 46. motive fluid will find its ray through the ports 48, groove 49 and ports 5() into the front end of the chamber 39, and acting against t-he front face of the flange 47,

will shift the valve rearwardly. This opens to atmosphere, port 5l from the chamber 39.. It cuts off motive fluid from the supply groove 33 to the interior of the valve, and at the same timey causes groove 4l with the pockets 42 to bring the supply groove 33 into communication with the groove 34. As; a. consequence motive fluid is now' directed into the passagewayv 35, and thence to the front end of the piston chamber, so that it operates on the front face of the piston head 19 and drives the piston rearwardly. The exhaustI now takes place from behind vthe piston through the ports 44, groove 43., groove 36, exhaust passageway 37 and valve 54, to atmosphere` When the piston enters the rear end portion of the valve, it builds up pressure that operates against Vthe rear end of said valve and the flange chamber 39 vadvance of the flange 4'? bei-ng now open to atmosphere, the valve will move forwardly, bringing it in a position to distribute motive fluidagainst the rear end of the piston to again drive it forwardly.

During this operation, it will be evident that whenever the piston moves forwardly, a part of the motive fluid behind it will enter the chamber 22 and pass by way of the bore 23 to the drill steel, and by means of the usual bore in said drill steel, will be delivered at the bottom of the drill hole to blow out the cuttings. This action is obviously intermittent. It is sometimes desirable to provide for a constant and augmented supply of cleansing air. lith the present structure this can be readily accomplished by turning the exhaust controlling valve 54 to closed position, or as shown in. Figure 3. When this occurs, obviously on the back stroke of the pistonv the air cannot exhaust thro-ugh the ports 44, groove 36 and passageway' 37 to at* mosphere, so that press-ure will occur through the branch 52 against `the rear face of the flange 47. The consequence is that the valve will be shifted, or if already shifted, will be held in its forward position.. As a result the piston will move. forwardly until it strikes the tool and will then beheld firmly against the tool. As the joint between the hammer extension and the rear'end of the tool is thus maintained tight andy a full supply of air is maintained behind the piston chamber, live air at substantially full line pressure will be inthe piston chamber behind the piston and a portion thereof will flow through the bore 23 to the steel and thence to the bottom of the drill hole. As soon as the valve 54 is .again turned to open position, the tool will start in operation. f

From the foregoing, it is thought that the construction, operation and many advantages of the herein described invention will be apparent to those skilled in the art, without further description, and it will be understood that various changes inthe size, shape, proportion and minor details of construction, may be resorted to without departing from the' spirit or sacrificing any of the advantages of the invention.

What I claim isf;

l. In a tool of the character set forth, the combination with a cylinder member and a reciprocatory piston therein,y of, a reciprocatory tubular distributing valve that re ce-ives the rear end of the piston, means c01itrolled by the valve for supplying actuating flu-id to its interior to act on the piston, and means in the valve controlled by the pis-- ton when in the valve, for directing the ac,- tuating fluid against a portion of the valve t0 shift said valve.

2. In a tool of the character set forth, the combination with a cylinder member and' a. reciprocatory piston therein, of a reciprocatory tubular distributing valve that receives the rear end of the piston and has an external flange, means controlled by the valve for supplying actuating fluid to its interior to act on the piston,l and means in the valve. controlled by the piston when in the valve, for directing the actuating fluid against'. the flange to shift said valve.

3. In a. tool of the Acharacter set forth, the combination with a cylinder member and a reciprocatory piston therein, of a reciprocatory tubular distributing valve that receives the rear end of the piston and has an external flange, means controlled by the valve for supplying actuating fluid to its; interior to act on the piston, and a passageway in the interior of the valve, having communication with the flange for directing fluid against the flange to shift the valve, communication between the Huid supply within the valve and the passageway being controlled by the rezr end of the piston when it is within the va ve.

4. In a tool of the character set forth, the combination with a cylindermember and a reciprocatory piston therein, of a reciprocatory tubular distributing valve that receives the rear end of the piston and has an external flange, means controlled by the valve for-supplying actuating fluid to its interior to act on the piston,said valve-having an enlarged bore in its front end that is entered by the rear end of the piston, and a passageway leading from said bore tothe flange, the rear end ofthe pis ton controllingv communication between the rear end of the valve bore and the passage.- way.

5. In a tool of the character set forth, the combination with a cylinder' member and a reciprocatory piston therein, of a reciprocatory tubular distributing valve that receives the rear end of the piston and has an external flange, means cont-rolled by the valve for supplying actuating Huid to its interi-orv to act on the piston, said valve having an en larged bore in its front end that is entered all lull

by the rear end of the piston, and a passage- Way leading from said bore to the flange, said passageway in turn being closed and opened by the valve, the rear end of' the piston controlling communication between the rear end of the valve bore and the passageway.

Y 6. In a tool of the character set forth, the combination with a cylinder member and a reciprocatory piston therein, of a reciprocatory tubular distributing valve through which the fluid passes to t-he cylinder and that receives the rear end of the piston and has an external flange, and a passageway to the flange from the interior of the valve, the supply of motive fluid to the passageway being controlled by the piston when in the valve.

7. In a tool of the character set forth, the combination with av cylinder member and a reciprocatory piston therein, of a reciprocatory tubular distributing valve that receives the rear end of the piston and has an external flange, said cylinder member having a chanr ber in which the flange operates, with a port to atmosphere that is covered and uncovered by the flange, and a passageway to the flange from the interior of the valve and having the fluid supply thereto controlled by the piston.

8. In a tool of the character set forth, the combination with a cylinder member and a reciprocatory piston therein, of a recipror catory tubular distributing valve that receives the rear end of the piston and has an external flange and an enlarged bore in its front end that is of greater diameter than the rear end of the piston, said valve having a port opening into the enlarged bore, said cylinder having a flange chamber in which the valve flange operates, and a passageway in the cylinder with which the port communicates, said passageway leading to the front end of the flange chamber, and the supply of motive fluid to the enlarged bore and the passageway being controlled by the piston when in the valve.

9. In a tool of the character set forth, the combination with a cylinder member and a reciprocatory piston therein, of a holder for the tool to be operated on by the piston, means for direct-ing motive fluid for hole cleansing purposes from the rear end of the cylinder member through the piston to a tool placed in the holder, an automatic valve for distributing motive fluid to the cylinder member to reciprocate the piston, and means for moving the valve to and holding it against operative movement in a position where the motive fluid is directed to the rear end of the cylinder member to hold the piston in its foremost position and maintain a constant pressure thereagainst and a firm bearing against the tool and a constant supply of cleansing fluid through the piston to the tool so borne against.

10. In a tool of the character set forth, the

combination with a cylinder member and a reciprocatory piston therein, of a holder for a tool in a position to be struck by the piston, means for directing motive fluid for hole cleansing purposes from the rear end of the cylinder member through the piston to such tool, an automatic valve for distributing motive fluid to the cylinder member to reciprocate the piston, and means for lnoving the valve to and holding it against operative movement in a position where the motive fluid is directed to the rear end of the cylinder member to hold the front end of the piston against the tool and maintain a contant pressure thereagainst to create a firm bearing against the tool and a constant supply of cleansing fluid through the piston to the tool so borne against.

11. In a tool of the character set forth, the combination with a cylinder member and a reciprocatory piston therein, of a holder for a tool to be operated on by the piston, an automatic valve for distributing motive fluid to operate the piston, an exhaust passageway for the distributed motive fluid, and means for directing the exhausting fluid against a portion of the valve to hold the valve against movement and thereby stop the operation of the piston.

l2. In a tool of the character set forth, the combination with a cylinder member and a reciprocatory piston therein, of a holder for a tool to be operated on by the piston, an automatic valve for distributing motive fluid to operate the piston, an exhaust passageway for the distributed motive fluid having a branch leading to the valve, and means for closing the exhaust passageway and thereby causing the fluid to pass to the valve and hold it against movement and thereby stop the operation of the piston.

13. In a tool of the character set forth, the combination with a cylinder member and a reciprocatory piston therein, of a holder for a tool to be operated on by the piston, an automatic valve for distributing motive fluid to operate the piston, said valve having an external flange, a chamber in which the flange operates, an exhaust passageway for the distributed motive fluid having a branch leading to the flange chamber, and a valve for closing the exhaust passageway beyond the branch.

14. In a tool of the character set forth, the combination with a cylinder member and a reciprocatory piston therein, of a holder for a tool to be struck by the piston, a passageway through the piston for delivering fluid from the rear end thereof to the tool for hole cleansing purposes, an automatic valve for distributing fluid to the piston to reciprocate it, said valve having a flange, a chamber in which the flange operates, an exhaust passageway for the piston actuating fluid controlled by the valve, a branch leading from 

